$_GET

$HTTP_GET_VARS [veraltet, nicht empfohlen]

(PHP 4 >= 4.1.0, PHP 5)

$_GET -- $HTTP_GET_VARS [veraltet, nicht empfohlen] — HTTP GET-Variablen

Beschreibung

Ein assoziatives Array von Variablen, die dem aktuellen Skript mittels der URL-Parameter übergeben werden.

$HTTP_GET_VARS enthält anfangs die selben Informationen, ist aber kein Superglobal. (Beachten Sie, dass $HTTP_GET_VARS und $_GET unterschiedliche Variablen sind und von PHP daher entsprechend behandelt werden.)

Changelog

Version	Beschreibung
4.1.0	Einführung von `$_GET` als Ablösung des bis dahin existierenden `$HTTP_GET_VARS`.

Beispiele

Beispiel #1 $_GET-Beispiel


<?php
echo 'Hallo ' . htmlspecialchars($_GET["name"]) . '!';
?>

Angenommen, der Benutzer gab ein http://example.com/?name=Hannes

Das oben gezeigte Beispiel erzeugt eine ähnliche Ausgabe wie:

Hallo Hannes!

Anmerkungen

Hinweis:
Dies ist eine 'Superglobale' oder automatisch globale Variable. Dies bedeutet, dass sie innerhalb des Skripts in jedem Geltungsbereich sichtbar ist. Es ist nicht nötig, sie mit global $variable bekannt zu machen, um aus Funktionen oder Methoden darauf zuzugreifen.

Hinweis:
Die GET-Variablen werden automatisch mit urldecode() behandelt.

Siehe auch

add a note

User Contributed Notes 10 notes

down

John Galt ¶

4 years ago


Just a note, because I didn't know for sure until I tested it.

If you have a query string that contains a parameter but no value (not even an equals sign), like so:
http://path/to/script.php?a

The following script is a good test to determine how a is valued:
<pre>
<?php
 print_r($_GET);
 if($_GET["a"] === "") echo "a is an empty string\n";
 if($_GET["a"] === false) echo "a is false\n";
 if($_GET["a"] === null) echo "a is null\n";
 if(isset($_GET["a"])) echo "a is set\n";
 if(!empty($_GET["a"])) echo "a is not empty";
?>
</pre>

I tested this with script.php?a, and it returned:

a is an empty string
a is set

So note that a parameter with no value associated with, even without an equals sign, is considered to be an empty string (""), isset() returns true for it, and it is considered empty, but not false or null. Seems obvious after the first test, but I just had to make sure.

Of course, if I do not include it in my browser query, the script returns
Array
(
)
a is null

down

zgold ¶

2 years ago


I don't directly use $_GET due to security concerns, instead I create a new array called $_CLEAN which contains cleaned superglobal variables.



<?php

function clean($elem)

{

    if(!is_array($elem))

        $elem = htmlentities($elem,ENT_QUOTES,"UTF-8");

    else

        foreach ($elem as $key => $value)

            $elem[$key] = $this->clean($value);

    return $elem;

}



$_CLEAN['GET'] = clean($_GET);

?>



I also do this for $_POST, as followed:

<?php $_CLEAN['POST'] = clean($_POST); ?>

down

Alberto Lepe dev at alepe dot com ¶

4 years ago


This Function will help you to manage your GET parameters to facilitate coding and prevent duplication. This is a basic version but it can be easily extended.

<?php
   // Author: Alberto Lepe (www.alepe.com)
    /* Process $_GET to preserve user custom parameters
     * the arguments is a list of URL parameters that should be removed/changed from URL
     * for example:
     *
     * URL = "index.php?s=1&fi=2&m=4&p=3
     *
     * if called: fixGet("s"); the result has to be: ?fi=2&m=4&p=3
     * if called: fixGet("s&m"); the result has to be: ?fi=2&p=3
     * if called: fixGet("s=4"); the result has to be: ?s=4&fi=2&m=4&p=3
     * if called: fixGet("s=2&m"); the result has to be: ?s=2&fi=2&p=3
     * if called: fixGet("s=&m=3"); the result has to be: ?s=&fi=2&m=3&p=3
     * if called: fixGet("s=2&m="); the result has to be: ?s=2&fi=2&m=&p=3
     * Special: when it ends with a =":" its to leave it open at the end
     * (just first occurrence) to facilitate concatenation:
     * if called: fixGet("s=2&m:"); the result has to be: ?s=2&fi=2&p=3&m
     * if called: fixGet("s=2&m:="); the result has to be: ?s=2&fi=2&p=3&m=
     * 
     * Usage with HTML (using the URL example above and $id = 99):
     * 
     * <a href="index.php<?php echo fixGet('m=2&s&fi:=').$id ?>" >Link</a>
     * Explanation: change "m" to 2, delete "s" and "fi" gets the $id value. ("p" is kept as it is not specified)
     * will output: <a href='index.php?m=2&p=3&fi=99'>Link</a>
     */
    public function fixGet($args) { 
        if(count($_GET) > 0) {
            if(!empty($args)) {
                $lastkey = "";
                $pairs = explode("&",$args);
                foreach($pairs as $pair) {
                    if(strpos($pair,":") !== false) {
                        list($key,$value) = explode(":",$pair);
                        unset($_GET[$key]);
                        $lastkey = "&$key$value";
                    } elseif(strpos($pair,"=") === false)
                        unset($_GET[$pair]);

                    else {
                        list($key, $value) = explode("=",$pair);
                        $_GET[$key] = $value;
                    }
                }
            } 
            return "?".((count($_GET) > 0)?http_build_query($_GET).$lastkey:"");
        }
?>

To test, copy+paste the following code into testFixGet.php

<?php
/*
 * Unit Test for fixGet()
 */
$cases = array (
    0 => array("s" => 1, "fi" => 2, "m" => 4, "p" => 3),
    1 => array("s" => "", "fi" => "", "m" => 4, "p" => 3),
);

$test[0] = array(
    "s" => "fi=2&m=4&p=3",
    "s&m" => "fi=2&p=3",
    "s=4" => "s=4&fi=2&m=4&p=3",
    "s=2&m" => "s=2&fi=2&p=3",
    "s=&m=3" => "s=&fi=2&m=3&p=3",
    "s=2&m=" => "s=2&fi=2&m=&p=3",
    "s=2&m:=" => "s=2&fi=2&p=3&m=",
    "z=9" => "s=1&fi=2&m=4&p=3&z=9",
    "z:" => "s=1&fi=2&m=4&p=3&z",
    "s:&m=3" => "fi=2&m=3&p=3&s",
    "s&m=3" => "fi=2&m=3&p=3",
);
$test[1] = array(
    "s" => "fi=&m=4&p=3",
    "s&m" => "fi=&p=3",
    "s=4" => "s=4&fi=&m=4&p=3",
    "s=2&m" => "s=2&fi=&p=3",
    "s=&m=3" => "s=&fi=&m=3&p=3",
    "s=2&m=" => "s=2&fi=&m=&p=3",
    "s=2&m:=" => "s=2&fi=&p=3&m=",
    "z=9" => "s=&fi=&m=4&p=3&z=9",
    "z:" => "s=&fi=&m=4&p=3&z",
);

foreach($cases as $x => $value) {
    echo "<hr> CASE: $x <hr>\n";
    foreach($test[$x] as $arg => $expected) {
        $_GET = $cases[$x];
        $res = myForm::fixGet($arg);
        echo (($res === "?".$expected)?"OK":"NG ($res)")." [$arg]<br>\n";
    }
}
?>

down

-2

Maarten Schroeven ¶

3 years ago


You can use this function to remove any $_GET variables out of your URL, it takes an array off strings(the names keys of the $_GET you wish to remove) and returns the url with the ones specified removed



<?php

  function getUrlWithout($getNames){

      $url = "http" . ((!empty($_SERVER['HTTPS'])) ? "s" : "") . "://".$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];

      $questionMarkExp = explode("?", $url);

      $urlArray = explode("&", $questionMarkExp[1]);

      $retUrl=$questionMarkExp[0];

      $retGet="";

      $found=array();

      foreach($getNames as $id => $name){

            foreach ($urlArray as $key=>$value){

                if(isset($_GET[$name]) && $value==$name."=".$_GET[$name])

                    unset($urlArray[$key]);

          }

      }

      $urlArray = array_values($urlArray);

      foreach ($urlArray as $key => $value){

          if($key<sizeof($urlArray) && $retGet!=="")

              $retGet.="&";

          $retGet.=$value;

      }

      return $retUrl."?".$retGet;

  }

?>



Example

current url is http://www.example.net/index.php?getVar1=Something&getVar2=10&getVar3=ok

<?php

    echo getUrlWithout(array("getVar1","getVar3"));

    //result will be "http://www.example.net/index.php?getVar2=10"

?>

down

-4

timberspine _AT_ gmail _DOT_ com ¶

6 years ago


Note that named anchors are not part of the query string and are never submitted by the browser to the server.

Eg.
http://www.xyz-abc.kz/index.php?title=apocalypse.php#doom

echo $_GET['title']; 

// returns "apocalypse.php" and NOT "apocalypse.php#doom"

you would be better off treating the named anchor as another query string variable like so:
http://www.xyz-abc.kz/index.php?title=apocalypse.php&na=doom

...and then retrieve it using something like this:
$url = $_GET['title']."#".$_GET['na'];

Hope this helps someone...

down

-4

chris at bjelleklang dot org ¶

3 years ago


Please note that PHP setups with the suhosin patch installed will have a default limit of 512 characters for get parameters. Although bad practice, most browsers (including IE) supports URLs up to around 2000 characters, while Apache has a default of 8000. 

To add support for long parameters with suhosin, add 
suhosin.get.max_value_length = <limit> in php.ini

down

-5

robotreply at gmail dot com ¶

5 years ago


Parsing of GET/POST drops duplicate variables unless those variables have "[]" (PHP bugs #10502, #15498 and #16195). Adding "[]" makes a mess of your javascript code, so here is a small workaround to it. 

This function basically scans your raw POST and GET input and tries to fix the same. This function must be called near the top of your script. Optimizations are welcome.

<?php
    function php_fix_raw_query() {
        $post = '';
         
        // Try globals array
        if (!$post && isset($_GLOBALS) && isset($_GLOBALS["HTTP_RAW_POST_DATA"]))
            $post = $_GLOBALS["HTTP_RAW_POST_DATA"];
         
        // Try globals variable
        if (!$post && isset($HTTP_RAW_POST_DATA))
            $post = $HTTP_RAW_POST_DATA;
         
        // Try stream
        if (!$post) {
            if (!function_exists('file_get_contents')) {
                $fp = fopen("php://input", "r");
                if ($fp) {
                    $post = '';
                     
                    while (!feof($fp))
                    $post = fread($fp, 1024);
                     
                    fclose($fp);
                }
            } else {
                $post = "" . file_get_contents("php://input");
            }
        }
         
        $raw = !empty($_SERVER['QUERY_STRING']) ? sprintf('%s&%s', $_SERVER['QUERY_STRING'], $post) : $post;
         
        $arr = array();
        $pairs = explode('&', $raw);
         
        foreach ($pairs as $i) {
            if (!empty($i)) {
                list($name, $value) = explode('=', $i, 2);
                 
                if (isset($arr[$name]) ) {
                    if (is_array($arr[$name]) ) {
                        $arr[$name][] = $value;
                    } else {
                        $arr[$name] = array($arr[$name], $value);
                    }
                } else {
                    $arr[$name] = $value;
                }
            }
        }
         
        foreach ( $_POST as $key => $value ) {
            if (is_array($arr[$key]) ) {
                $_POST[$key] = $arr[$name];
                $_REQUEST[$key] = $arr[$name];
            }
        }
                 
        foreach ( $_GET as $key => $value ) {
            if (is_array($arr[$key]) ) {
                $_GET[$key] = $arr[$name];
                $_REQUEST[$key] = $arr[$name];
            }
        }

    # optionally return result array 
        return $arr;
    }
 

?>

down

-6

Z80user ¶

1 year ago


in MySQLi

I need write
-. $_GET[actor]
instead of
-. $_GET["actor"]
or
-. $_GET['actor']

NOTE: IIS 7.5 (On Windows Server 2008 R2 Datacenter) with PHP Version 5.4.12 and mysqlnd 5.0.10
Version of MySQL 5.6.10

This code show a Movies with an actor ID_Actor
E.G. URL "http://127.0.0.1/test2.php?actor=14"
<?php
// CONNECT TO THE DATABASE
    $DB_HOST = '';
    $DB_USER = '';
    $DB_PASS = '';
    $DB_NAME = '';
    
    $mysqli = new mysqli($DB_HOST, $DB_USER, $DB_PASS, $DB_NAME);
    
    if (mysqli_connect_errno()) {
        printf("Connect failed: %s\n", mysqli_connect_error());
        exit();
    }

// A QUICK QUERY ON A FAKE USER TABLE

    $query = "SELECT DISTINCT Title FROM movie WHERE ID_movie IN ( SELECT DISTINCT ID_Movie FROM actor_scene WHERE ID_actor=$_GET[actor]) ";
    $result = $mysqli->query($query) or die($mysqli->error.__LINE__);

// GOING THROUGH THE DATA
    if($result->num_rows > 0) {
        while($row = $result->fetch_assoc()) {
            echo stripslashes($row['Title'])."<br>";
            echo " ";
        }
    }
    else {
        echo 'NO RESULTS';
    }
// CLOSE CONNECTION
    mysqli_close($mysqli);
?>

down

-12

Daniel M ¶

3 years ago


If you need to find out whether any GET variables have been specified, you can use the empty() function.



<?php



if(empty($_GET))

    echo "No GET variables";

else

    print_r($_GET);



?>



empty() - http://php.net/manual/en/function.empty.php

print_r() - http://php.net/manual/en/function.print-r.php

down

-8

slavik0329 ¶

5 years ago


the addget function below actually has more use when you dont use the recursive merge as such:



<?php



function AddGet($ArrayOrString){

if(is_array($ArrayOrString))

return http_build_query(array_merge($GLOBALS['_GET'], $ArrayOrString));

parse_str($ArrayOrString, $output);

return http_build_query(array_merge($GLOBALS['_GET'], $output));

}



?>



In this case, if the key is added again with a different value it will be replaced with the new value.



addget("change=true"); // ?change=true

addget("change=false"); // ?change=false

add a note